This center is spread over three separate buildings: the Everett McKinley Dirksen Building; the John C. Kluczynski Building (230 S. Dearborn), which includes the Loop's post office; and the Metcalfe Building (77 W. Jackson). Designed in 1959, but not completed until 1974, the severe constellation of buildings around a sweeping plaza was Mies van der Rohe's first mixed-use urban project. Fans of the International Style will groove on this pocket of pure modernism, while others can take comfort in the presence of the Marquette Building, which marks the north side of the site. In contrast to this dark ensemble are the great red arches of Alexander Calder's Flamingo. The area is bounded by Dearborn, Clark, and Adams streets and Jackson Boulevard.